This Specimen has been sold.
Trilobite Cruziana (Trackway) & Rusophycus (Resting Spot) - Morocco
This is a cool plate with two arthropod trace fossils, likely trilobite, from near Erfoud, Morocco. This Cruziana is a 2.7" trackway preserved in a slab of mudstone and would be Ordovician in age or approximately 450 million years old. There is also a rusophycus or resting spot preserved.
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.